-
[show abstract]
[hide abstract]
ABSTRACT: Gramoxone, containing paraquat as an active ingredient can cause severe lung injury in both humans and experimental animals. Biologically active fibroblast-stimulating factors produced by lymphocytes and macrophages may be of importance in the development of interstitial fibrosis. In our present study we have attempted to inhibit the process of paraquat induced lung fibrosis by lymphokine-enriched supernatants from concanavalin A stimulated spleen cell cultures. It was found that adequate supernatant treatment significantly reduced PQ-induced lung injury and its associated inflammatory response.
Experimental pathology 02/1990; 38(3):189-95.
-
[show abstract]
[hide abstract]
ABSTRACT: 1. Studies were made to prove that a shift in the eicosanoid metabolism plays a role in the lung-damaging action of paraquat, the active ingredient of Gramoxone, in mice. 2. An attempt was made to inhibit the eicosanoid metabolism with acetylsalicylic acid (Aspisol). Among others, it was found that the metabolic effect impaired by paraquat is influenced in a favourable direction by Aspisol treatment, including the % of survival, the lipid peroxidation values and the superoxide dismutase activity in the lung. 3. At the same time, as a prostacyclin synthesis activator, paraquat participates in the efforts of the organism to eliminate the toxic material, but it later weakens the defence mechanisms by enhancing thromboxane A2 synthesis, and it initiates pulmonary fibrosis, which cannot then be averted with Aspisol.
Acta Biologica Hungarica 02/1988; 39(4):351-9. · 0.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The mouse footpad swelling test was used to clarify the possibility of the induction of local cellular reaction with cell suspension of mouse lungs treated with paraquat in a syngeneous animal. Among the inbred strains used, the highest, statistically significant cellular reactivity was observed in C3H/He strain mice. These results suggest indirect evidence of macrophage activation in the lung toxicity of paraquat.
Experimental pathology 02/1988; 34(2):115-8.
-
[show abstract]
[hide abstract]
ABSTRACT: The herbicide Gramoxone (the active ingredient is paraquat) actively accumulates in the lung in the mammalian organism, where it exerts its toxic effect through the generation of oxygen radicals. Efforts were made to counteract the toxic effect in experiments in mice. Its penetration into the cells was blocked with the diamines putrescine and cadaverine. The synthesis of the prostaglandins, which are supposed by responsible for the acute symptoms, was inhibited with Aspisol. Accumulation inhibition with biogenic amines is considered the most effective.
General Pharmacology 02/1987; 18(2):129-32.
-
[show abstract]
[hide abstract]
ABSTRACT: The role of light is known to be important in the herbicidal action of paraquat, the active ingredient of Gramoxon. Experiments were therefore performed to establish whether illumination influences paraquat toxicity in some way in mice. Besides the 72-hr survival rate, studies were made of the body weight/lung weight ratio, the antioxidant enzyme activity and the lipid peroxidation in mice treated with the LD50 of paraquat and kept in the dark or under illumination. All of the measured parameters indicate that illumination enhances the toxic properties of paraquat in mice.
General Pharmacology 02/1986; 17(3):359-62.
-
[show abstract]
[hide abstract]
ABSTRACT: The effects of the simultaneous administration of ascorbic acid and the LD50 of paraquat (an ingredient of Gramoxone), and of ascorbic acid pretreatment followed by the LD50 of paraquat, were studied on the phospholipid and triglyceride fatty acid levels in homogenates of mouse lung, liver and kidney. Ascorbic acid treatment increases the content of polyunsaturated fatty acids in the lung considerably, i.e. the pulmonary membrane fluidity decreases significantly in response to ascorbic acid. In the liver homogenate, the membrane fluidity is significantly increased by ascorbic acid pretreatment, and significantly decreased by simultaneous ascorbic acid treatment. In the renal tissue, the result of ascorbic acid pretreatment exhibits a similar tendency to that of paraquat treatment, but a more significant one, while the administration of ascorbic acid together with paraquat does not cause a substantial change in the fluidity index compared to the control.
General Pharmacology 02/1986; 17(3):363-5.
-
[show abstract]
[hide abstract]
ABSTRACT: It was demonstrated that cysteine and D-penicillamine are able to replace reduced glutathione to some extent in the glutathione peroxidase reaction. An in vivo study was made of the role played by--SH compounds in the antioxidant enzyme system involved in the detoxication of the LD50 of paraquat (PQ), and hence of their role in the detoxication of PQ. The effectiveness was D-PA greater than GSH greater then Cys in the liver and GSH greater than Cys greater than D-PA in the lung.
Comparative Biochemistry and Physiology Part C Comparative Pharmacology and Toxicology 02/1986; 83(1):149-53.
-
[show abstract]
[hide abstract]
ABSTRACT: The effects of paraquat, the active ingredient of Gramoxone, were studied on frogs (Rana esculenta) kept at 4 degrees C or 20 degrees C, to establish its effects on the survival, the antioxidant enzyme system and the lipid peroxidation of the tissues (liver and lung). The lower temperature was found to increase the survival. The activities of the antioxidant enzymes were decreased or not influenced by the LD50 of paraquat at the lower temperature, whereas the LD100 often resulted in a significant enzymatic activity increase. It was an important finding that the lipid peroxidation of the lipid decreased in response to paraquat at 4 degrees C, but increased at 20 degrees C. The lipid peroxidation of the lung increased at both temperatures.
Acta Biologica Hungarica 02/1985; 36(3-4):295-300. · 0.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The effects of Gramoxone on the redox state potential (E'0) of the liver, heart, skeletal muscle and lung of guinea-pig were examined at different times. The E'0 values were compared with control measurements. Gramoxone was found to cause mainly a significant E'0 increase with time in lung tissues. This lends support to the general experience that the primary target organ for paraquat (PQ) toxicity is the lung. It is suggested as explanation of the observation that the lung is most actively connected with molecular oxygen.
Acta Biologica Hungarica 02/1985; 36(3-4):301-3. · 0.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A study was made of the peroxide metabolism enzymes in carp fish, and of the effects on these of three different concentrations of the herbicide paraquat. Mainly the changes in the superoxide dismutase, catalase and lipid peroxidation resembled the changes observed in previous intoxication studies on mammals.
Acta Biologica Hungarica 02/1984; 35(1):91-6. · 0.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Investigation has been made of how the LD50 and LD100 of PQ influence the peroxide metabolism enzymes and lipid peroxidation in organ homogenates and blood samples of the rat. The peroxide metabolism enzyme activities were changed in a concentration dependent manner. In general, the effect of the lower doses of PQ on the superoxide dismutase, catalase activities and lipid peroxidation are increased. The glutathione peroxidase activity was decreased. Higher doses of PQ enhanced all of enzyme activities and lipid peroxidation studied.
General Pharmacology 02/1984; 15(2):133-7.
-
[show abstract]
[hide abstract]
ABSTRACT: 1. We have studied the effects of the LD50 and LD100 of paraquat on mouse blood triglycerides and on the time-dependence of the blood clotting, the bleeding time, the number of thrombocytes, and the body temperature. 2. The examined components vary rapidly in response to the toxic doses of paraquat. The changes depend on, among others, the amount of paraquat administered. 3. They are suitable for rapid diagnosis and for establishment of the severity of the poisoning.
General Pharmacology 02/1983; 14(3):381-3.
-
[show abstract]
[hide abstract]
ABSTRACT: The effects of a 7-day treatment with Haloperidol or reserpine (in both cases 0.1 mg/kg per day) were studied on the superoxide dismutase and catalase activities and the lipid peroxidation in various discrete regions of the rat brain. It was found that these neuroleptics change the lipid peroxidation and the activities of the enzymes in similar directions in the brain areas tested.
General Pharmacology 02/1983; 14(5):537-9.
-
[show abstract]
[hide abstract]
ABSTRACT: Following administration of the LD50 or the LD100 of Gramoxon (PQ), the phospholipids (PL) of the lung, liver and kidney were separated and both the PLs and the fatty acids isolable from them were examined quantitatively. The different doses of PQ caused different changes of the saturated and unsaturated fatty acids in the various organs. The changes in the PL unsaturated fatty acids point to PQ-induced lipid peroxidation enhancement and membrane damage.
General Pharmacology 02/1983; 14(5):541-4.
-
[show abstract]
[hide abstract]
ABSTRACT: 1. Guinea-pigs, which exhibit a similar metabolism to that of man insofar as they are incapable of synthesizing ascorbic acid, were poisoned with Gramoxon containing the LD50 or LD100 of paraquat. 2. A study was made of how the paraquat poisoning affected previously investigated tissue parameters, the superoxide dismutase, catalase and glutathione peroxidase activities and the lipid peroxidation. 3. In accordance with earlier results, the paraquat influences these parameters in different ways in all the tissues examined, depending on its concentration. 4. These parameters comprise primarily affected systems as regards paraquat toxicity.
General Pharmacology 02/1982; 13(2):133-7.
-
[show abstract]
[hide abstract]
ABSTRACT: 1. Substances previously tested therapeutically were studied to obtain evidence on the pathomechanism in mice of paraquat, the active ingredient of Gramoxon, connected with the radicals formed from molecular oxygen, and also to extend the therapeutic possibilities. 2. The effects of these substances were assessed on the basis of the 72-hr survival rate and the percentage ratio of the wet lung weight to the overall body weight. 3. Other toxicological parameters too were followed. 4. Our present investigations indicate that, in agreement with our earlier results, besides reduced glutathione and ascorbic acid, vitamin E and C-ase are of the greatest importance from the aspect of the protection against paraquat toxicity. 5. In addition to those listed, other materials too, e.g. antifibrotic substances, naturally possess considerable detoxicating properties too.
General Pharmacology 02/1982; 13(4):333-41.
-
General Pharmacology 02/1981; 12(4):225-7.
-
General Pharmacology 02/1981; 12(4):229-31.
-
General Pharmacology 02/1980; 11(6):569-72.
-
General Pharmacology 02/1980; 11(6):573-4.
